Design and implementation of a routing protocol for mobile AD-HOC networks

Mobile ad-hoc network is a network of wireless mobile nodes without any centralized administration. In mobile adhoc network, the topology of the network changes periodically. Since there is a periodic change in the topology, routing updates must take place frequently. This may increase the overhead in the network. Hence, there is a need to develop an adhoc routing protocol which reduces the control overhead involved in ad-hoc routing.

In this paper, an ad-hoc routing protocol, called Extended Routing Information Protocol (ERIP)is designed. This protocol is characterized by beaconless transmission, loop free operation, encrypted routing information, power conservation and low control overhead. An incremental dump strategy of forwarding only the changed routing entries to the next hop neighbours is used for exchanging the routing information among the ad-hoc network nodes. This helps in reducing the control overhead. ERIP is a proactive routing protocol for avoiding routing delays. The developed protocol is secured by encrypting the routing information before forwarding it to the other nodes. The designed ERIP is simulated and tested by integrating it with QualNet simulator. In static scenarios, ERIP does not send out any routing updates after establishing the initial route, because the node positions are unchanged. In dynamic scenarios, routing updates become more frequent in direct proportion to network complexity. ERIP offsets this overhead because the size of the update messages is considerably lesser than that of most of the other proactive protocols.

The performance of ERIP was compared with that of two other industry standard protocols, Optimized Linked State Routing (OLSR) Protocol and Dynamic Source Routing (DSR) Protocol. The performance test results showed that the latency and jitter of data transmission of ERIP is least when compared to that of OLSR and DSR. It was also observed that ERIP achieves this better performance with very little degradation of throughput and packet delivery ratio. Present results show that ERIP takes just about 1/3rd the time taken by other proactive routing protocols such as Optimized Linked State Routing (OLSR) protocol to establish the initial route.